Method of operating propulsion devices



Nov. 28, 1961 I w, MULLEN ll, EIAL 3,010,279

METHOD OF OPERATING PROPULSION DEVICES 5 Sheets-Sheet 1 Filed April 8. 1957 INVENTOR JAMES W. MULLENII JOHN B. FENN FRANK I. TANCZOS BY LQMM ATTORNEYS 28, 1961 J. w. MULLEN n, ETAL 3,010,279

METHOD OF OPERATING PROPULSION DEVICES Filed A ril 8. 1957 5 Sheets-Sheet 2 INVENTOR MULLEN H w. B. PENN FRANK 1. TANCZOS BY HWY. fiz AWL AM ATTORNEY;

Nov. 28, 1961 .1. w. MULLEN ll, ETAL 3,0

METHOD OF OPERATING PROPULSION DEVICES 5 Sheets-Sheet 3 Filed April 8. 1957 INVENTOR JAMES W. MULUEN 11 JOHN E). FENN FRANK 1. TANCZOS BY Mar &2 we/1.. M

ATTORNEY! Nov. 28, 1961 J. W. MULLEN ll, EI'AL METHOD OF OPERATING PROPULSION DEVICES Filed April 8. 1957 5 Sheets-Sheet 5 I H6 f 114 I26 so 2 4 I30 84 INVENTORS JAMES W. M LLEN 11 JOHN B FEIHN ATTORNEY) 3,010,279 NIETHOD F OPERATING PROPULSION DEVICES James W. Mullen H, Richmond, Va., John B. Fenn, Princeton, N.J., and Frank I. Tanczos, Washington, D.C., assignors to Texaco Experiment Incorporated, a corporation of Virginia Filed Apr. 8, 1957, Ser. No. 651,548

7 Claims. (Cl. 60-3548,)

These and other objects of the present invention will be more clearly apparent to those skilled in the art when considered with the following brief description of the present invention, and the detailed description thereof with reference to the specific embodiments disclosed for the purpose of illustration of the principles of the invention.

Briefly, the present invention is directed to an improved method for promoting the continuous decomposition of compounds and mixtures thereof which decompose with the release of large quantities of heat to form decomposition products which include substantial quantities of solid carbon, and gaseous decomposition products.

In general, the fuels contemplated as within the scope of the present invention are those which decompose with the liberation of heat into an oxidizable decomposition mixture which includes solid carbon particles.

The fuels used in the method of the invention are acetylenic compounds and mixtures of such compounds with each other and with solvents or miscible liquids. Included in the fuels useful in the method of the invention are: acetylenic hydrocarbons, such as acetylene, propyne, including its tautomer, allene, and mixtures thereof with propyne, dimethyl acetylene ethylacetylene and their tautomer 1,3-butadiene, vinylacetylene, a-methylbutene 1-yne-3, Z-methyldivinyl-acetylene, diacetylene, 1,5-hexadiyne, 1,6-heptadiyne, and 1,7-octadiyne; and other acetylenic compounds, particularly the propargyl compounds, suchas dipropargyl ether, propargyl alcohol mixtures. Among the non-acetylenic compounds which may be admixed with the acetylenic compounds are hydrocarbons, such. as, kerosene, octane, octene, benzene and other non-acetylenic hydrocarbons containing from about 6 to about 15 carbon atoms, and solvents for the acetylenic compounds, such as acetone and the like.

' In general, where compounds which are subject to decomposition with the liberation of heat into combustible decomposition products which include carbon are admixed with non-acetylenic hydrocarbons to form a fuel for use in the method of the present invention from about 0% to about 20% hydrocarbons will provide .very satisfactory results However, such mixtures preferably contain not more than 15% of hydrocarbon.

Of the substantial number of compounds and-admixtures which provide satisfactory utility in the method of the present invention it has been found that the fol- V lowing are particularly advantageous:

Propyne, including its tautomer, allene and admix tures thereof with propyne; propargyl compounds particularly dipropargyl ether, propargyl alcohol andpropargyland the mono-, diand tri-propargylamines, alone. or in' dfiifiifi Patented Nov, 28, 1961 amines; and the diacetylenic hydrocarbons particularly 1,5-hexadiyne, 1,6-heptadiyne and 1,7-octadiyne.

The above listed compounds are particularly advantageous because of the large quantities of heat liberated upon decomposition, their relative stability, their availability in large quantities and their adaptability to the method of the present invention. Table I shows some of the chemical and physical properties of some of these preferred fuels.

Table I Adiahatie Decomposition Products Molccewuilibrinn Moles per Mole of fuel Fuel ul tr decomposition Weight temperature,

F. C 11: CH, Other Propyne 40.06 2, 523 2. 96 1.92 0.04 Proparg vl ether 94:1 2, 949 4.98 2. 95 0.-03 l 00 1,6-FIoot-adiyne 92.13 2, 630 6.91 3.82 0. 09 1,7-Octadiyne 106.16 2, 7. 69 4. 38 0.31

Throughout the specification and claims the terms decomposition mixture means a mixture of the prod-.

nets of decomposition of acetylenic compounds into their elements or into mixtures of elementsand simple com}. pounds, or admixtures of "said decomposition,products,

with organic compounds.

The effective utilization of jthe aforementioned fuels? byithe methods of the present invention which generally comprisesdirecting fuels subject to exothermic decomposition with the formation of solid carbon particles and gaseous. decomposition products into a confined zone maintained at conditions of temperature and pressure effective to cause the fuels to decompose and removing the.

products of decomposition at least at sonic speed from the confined zone while continuing to maintain said conditions of temperature and pressure in the confined zone, will be more particularly described as applied to the reaction propulsion engine shown in the accompanying drawings in which:

. FIG. 1 is a side view of a reaction propulsion engine adapted for carrying out the methods of the invention;-

FIG. 2 is a longitudinal, sectional view through the device shown in FIG. 1 with parts of the internal mechanisrns shown in section;

FIG. 3 is an enlarged sectional view of the forward portion of the rocket shown in FIG. 1;

FIG. 4 is a section substantially on line 4-4 of FIG. 3;

'FIG. 5 isa section substantially on line 55 of FIG. 3; v

FIG. 6 is an enlarged sectional view of portion of the device shown in FIG. 1;

FIG. 7 is a section substantially on line 77 of FIG. 6;

FIG.. 8 is an enlarged fragmentary view substantially.

on line 88 of FIG. 6;

'FIG. 9 is an enlarged fragmentary view in partial section of a fuel metering system shown in FIG. 3;

FIG. 10 is an enlarged sectional view substantially on line 19-10 of FIG. 9; and

FIG. 11 isan enlarged fragmentary view of the control valve and nozzle construction for the rocket chamber of the device shown in FIG. 1.

",With reference to the drawings there is shown a rocket type reaction propulsion engine embodied in a missile which generally comprises an elongated housing or shell 10 having a streamline nose portion 12, an elongated body portion 14, and a tail portion 16 which tail portlon may be provided with stabilizing fins 18 as is well known in the art.

v The nose portion12 of the reaction propulsion vehicle 1 1s shown, for convenience, as being small in size andenthe rearward closing only the fuel metering mechanism of the reaction propulsion motor. However, it will be appreciated that rockets constructed in accordance with the principles of this invention would be provided with a nose section suitable for the particular use to which the vehicle-is designed.

For example, if the device were to be employed as a missile the nose portion would house suitable high. explosives and detonating devices therefor and where desired, control means for guiding the missile to a target. If the rocket is to be used for obtaining meteorological data or the like at high altitudes suitable indicating, recording and/ortelemetering equipment would be provided in the nose section. I 7

Within the shell 10 of the rocket, proceeding from the forward end rearwardly, are housed the following structures each of which will be described in detail hereinafter.

Fuel regulator and control mechanism 20, high pres sure gas storage compartment 22, fuel storage tank 24, fuel flow initiating valve 26, rocket chamber 28 and from its seat,96 so that the gas of-air flowingout of the space ahead ofthe bladder passes throughconduit nozzled outlet 30. t

The fuel designated 32 is stored in elongated cham position during the filling of the gas storage chamber 24.

to prevent the passage of gas to the gas flow regulator 50. In general, suitable operation is provided by preloading the tank 22 with nitrogen at about, 2500 pounds per square inch. t

When the valve .48 is manually opened, access being had thereto by the removal'of plug 52 in the skin of the In order to transferthe plurality of fuel nozzles 84 positioned at the upstream end of the rocket chamber 28.

. Referring to FIG. 9 the fiow initiating valve 26 includes an inlet opening for fuel 84' and a poppet valve 86 which in the closed position seats about the flange 88" formed in the valve body; Helical spring 90-urges the poppet'valve 86 against theseat 88. At the lower end of the valve body isprovided a spring urged ball check" 92 which permits communication with an opening 94 for use in filling the fuel chamber 24 with fuel. During I V the filling of the fuel tank the spring urgedball check 92 moves away from its normal seatedposition and-fuel flows through tthe passage 84,'the conduit 82-and'into thetank 24 forcing thebladder 36 towards the forward end of the fuel chamber 24. Gas or air at the forward;

end of the bladder 36 is bled therefrom after manual, movement of the poppet 74 of valve (FIG. 9) away 110; where it exhausts to atmosphere through outlet 112.

Referring again to flow initiation valve 26, the poppet V valve 86 is, moved to the unseated position by a powder charge '114 carried in a pocket in movable piston 116,

slidably connected to the upper end 118 of the poppet valve 86. An electric igniter 1 20, for charge 114, is connected to an external electrical source through electrode 122. Upon. excitation of the igniter 120, the powder charge 114 burns, forcing the piston 116-and the poppet valve 86 downwardly so that fuel pressurized, as

hereinbefore described, will flow from the inlet of the. valve 84 pass the valve seat 88 and into the plenum.

chamber 124. A. spring type snapring 126 movesinto groove 128 when the poppet valve 86 is moved downwardly by the force of the powder charge 114 so that the valve poppet 86 isheld in the open position, 1.

Fuel entering the plenum chamber 124 passes through the plural passages 130 then, into the nozzles 84 from missile, the compressed gas flows through the valve 48 duit 56.

The pressure regulator 50 may be of the type shown in detail in FIG. 10 wherein a valve of the poppet type 58 is moved relative to its seat by predetermined presto the conventional pressure regulator 50. through consure maintained in chamber 62 acting upon diaphragm 64. An opening closed by plug 66 is provided to preload the pressure chamber 62. The compressed nitrogen flowing from nitrogen storage chamber 24 through conduit 56 into chamber 68 issues therefrom through con- In operation of the device the valve poppet 72 is moved away from its seat 78. so that the gaseous pressurizing medium may flow from outlet 42 and throughconduit 40, which passes through the nitrogen storage compartment 22, and into the fuel storage chamber 24 on the bladder side of the fuel 32 whereby the bladder which it is sprayed into the rocket chamber 28.

At the. forward end of the rocket chamber 28 is.provided a small'electrically initiated fiare l32- which is connected toian external sourceof electric'power" through electrode 134. The initiation of the electric time 1321 causes the.,hot products of the burning. flare to issue 'into' the rocket chamber 28.j Thehot products of corn bustion from the flare132 initiate the decomposition of the novel fuels of the present invention. Once. decom! position is started, the pressure and temperature within the chamber 28 raiseto levels at- Which the decomposi- 'tion of freshly injected fuel is self-supportingand proceedsfsmoothly and'continuously. Decomposition products ofthe fuel issue from rocket chamber 28' through 1 the nozzle 30 positioned at the rearward end of the rocket chamber 28. To provide continuous decomposition, of. the fuel a critical pressure and temperature isto maintain at least choking conditions in chamber 28 willdepend upon thecharacteristics of the fuel and rate of decomposition thereof and choking will occur when- ..the conditions of operation.

36 is urged toward the discharge end of the fuel chama ber forcing the fuel through the plural outlets- 80, more clearly shown in FIG. 9 and conduit 82 to the flow initiats valve 26, th d s h e P rt ptwhish ctmnects t ever there is a restriction effective toproducea pressure ratio across the restriction of the order of 2 to lunder In-the form of the invention shown the nozzle 30 represents such a physical restriction.

When using propyne per square inch and the adiabatic equilibrium decomposition temperatu're is about 2520 F. 'at300'-p.s.i'.a..

The shape and size of the rocket chamberwill depend With' as the fuel the minimum pressure to sustain the decompositionthereof is about 135 pounds pound of hydrogen and about 1700 t The high velocity stream of hydrogen containing suspended carbon particles issuing from the nozzle 30 provides the thrust for the vehicle.

Since the hydrogen and carbon from the decomposition of, for example propyne, leave the rocket or decomposition chamber 28, at about 1800 F. static temperature portions of the combustible mixture formed with the surrounding air are in the autoignition region.

Employing propyne as the fuel, the rocket cycle brought about by the decomposition of the fuel in decomposition chamber 42 produces an ideal specific impulse of about 189 seconds at 315 pounds per square inch absolute.

A further example of the operation of reaction propulsion devices by the method the present invention is as follows:

One hundred pounds of liquid propyne CH3-CECH is placed in fuel storage tank 24 and the pressurized gas storage tank 22 is filled with nitrogen at 3500 pounds per square inch. The volume of the gas storage tank 22 being about 0.8 cubic foot.

The nozzles 84 are set to deliver a total of about 3.6 pounds of propyne per second into the decomposition chamber having a diameter of 12 inches, a length of 8 inches and an outlet diameter of 2.86 inches at exit and 1.43 at smallest area.

The flow initiation valve 26 and the flare 123 are electrically actuated.

The burning flare causes the pressure and temperature in the rocket chamber to build up and initial flow of propyne into the chamber to decompose into carbon, and hydrogen with the liberation of about 1,700 B.t.u.s per pound of fuel.

Choking conditions maintained within the chamber 28 by the outlet nozzle 30 causes the remainder of the fuel injected into the chamber to continuously decompose and the process continues automatically until the liquid propyne in tank 24 is exhausted (about 27 seconds), producing about 600 pounds of thrust.

From the foregoing description of the invention and the means for carrying out the invention it will be seen that revolutionary new processes for the operation of reaction propulsion engines have been provided satisfying the aims, objects and advantages of the invention.

This application is a continuation-in-part of application Serial No. 239,952, filed August 2, 1951, now abandoned.

We claim:

1. A method of operating a reaction propulsion engine which comprises directing acetylenic fuels selected from the group consisting of acetylenic hydrocarbons and tautomers thereof, dipropargyl ether, propargyl alcohol and mono-, diand tri-propargylamine subject to exothermic thermal decomposition with the formation of solid carbon particles and gaseous decomposition products into a confined zone maintained at conditions of temperature and pressure effective to cause the fuels to decompose exothermically and permitting the products of decomposition to flow at least at sonic speed from the confined zone while continuing to maintain said conditions of temperature and pressure therein.

2. A method of operating a reaction propulsion engine which comprises directing fuels consisting of a mixture of acetylenic compounds selected from the group consisting of acetylenic hydrocarbons and tautomers thereof, dipropargyl ether, propargyl alcohol and mono-, diand tripropargylamine and organic compounds selected from the group consisting of non-acetylenic hydrocarbons containing from about 6 to about 15 carbon atoms and acetone subject to exothermic thermal decomposition with the formation of solid carbon particles and gaseous decomposition products, said mixture containing at least of acetylenic compounds, into a confined zone maintained at conditions of temperature and pressure eifective to cause the fuels to decompose exothermically and permitting the products of decomposition to flow at least at sonic speed from the confined zone while continuing to maintain said conditions of temperature and pressure therein.

3. A method of operating a reaction propulsion engine which comprises directing fuels comprising at least 80% of acetylenic compounds selected from the group consisting of acetylenic hydrocarbons and tautomers thereof, dipropargyl ether, propargyl alcohol and mono-, diand tri-propargylamine subject to exothermic thermal decomposition with the formation of solid carbon particles and gaseous decomposition products into a confined zone maintained at conditions of temperature and pressure effective to cause the fuels to decompose exothermically and permitting the products of decomposition to flow at least at sonic speed from the confined zone While continuing to maintain said conditions of temperature and pressure therein.

4. A method of operating a reaction propulsion engine which comprises directing acetylenic hydrocarbons subject to exothermic thermal decomposition with the formation of solid carbon particles and gaseous decomposition products into a confined zone maintained at conditions of temperature and pressure effective to cause the fuels to decompose exothermically and permitting the products of decomposition to flow at least at sonic speed from the confined zone while continuing to maintain said conditions of temperature and pressure therein.

5. A method of operating a reaction propulsion engine which comprises directing propyne into a confined zone maintained at conditions of temperature and pressure elfective to cause the propyne to decompose exothermically and permitting the products of decomposition to flow at least at sonic speed from the confined zone while continuing to maintain said conditions of temperature and pressure therein.

6. A method of operating a reaction propulsion engine which comprises directing dipropargyl ether subject to exothermic thermal decomposition with the formation of solid carbon particles and gaseous decomposition products into a confined zone maintained at conditions of tempera ture and pressure effective to cause the fuels to decompose exothermically and permitting the products of decomposition to flow at least at sonic speed from the confined zone while continuing to maintain said conditions of temperature and pressure therein.

7. A method of operating a reaction propulsion engine which comprises directing diacetylenic hydrocarbons. subject to exothermic thermal decomposition with the formation of solid carbon particles and gaseous decomposition products into a confined zone maintained at conditions of temperature and pressure eifective to causethe fuels to decompose exothermically and permitting the products of decomposition to flow at least at sonic speed from the confined zone while continuing to maintain said conditions of temperature and pressure therein.

References Cited in the file of this patent UNITED STATES PATENTS 2,573,471 Malina et al. Oct. 30, 1951 2,648,317 Mikulasek et al. Aug. 11, 1953 2,702,984 Britton et al. Mar. 1, 1955 OTHER REFERENCES Coast Artilley Journal, November-December 1947, pp. 30-33, 52/0.5(S), (article by Ley). 

1. A METHOD OF OPERATING A REACTION PROPULSION EN
 1. A METHOD OF OPERATING A REACTION PROPULSION ENGINE WHICH COMPRISES DIRECTING ACETYLENIC FUELS SELECTED FROM THE GROUP CONSISTING OF ACETYLENIC HYDROCARBONS AND TAUTOMERS THEREOF, DIPROPARGYL ETHER, PROPARGYL ALCOHOL AND MONO-, DI- AND TRI-PROPARGYLAMINE SUBJECT TO EXOTHERMIC THERMAL DECOMPOSITION WITH THE FORMATION OF SOLID CARBON PARTICLES AND GASEOUS DECOMPOSITION PRODUCTS INTO A CONFINED ZONE MAINTAINED AT CONDITIONS OF TEMPERATURE AND PRESSURE EFFECTIVE TO CAUSE THE FUELS TO DECOMPOSE EXOTHERMICALLY AND PERMITTING THE PRODUCTS OF DECOMPOSITION TO FLOW AT LEAST AT SONIC SPEED FROM THE CONFINED ZONE WHILE CONTINUING TO MAINTAIN SAID CONDITIONS OF TEMPERATURE AND PRESSURE THEREIN. 